NEW YORK -- At least two U.S. teenagers have suffered serious injuries, including one left paralyzed with permanent brain damage, by stunts done to imitate MTV’s “Jackass.”

Marc Leroux actually returned to doing stunts for video after receiving serious burns when he poured gas on his pants and ran over a burning railroad tie when he was 14, ABC News reports. The video of his stunt showed him screaming in pain while the flames burned his legs.

"The skin was pink and peeling everywhere and there was pus and fluid dripping from my leg onto the ground," Marc said. "I've never smelled anything worse than that."

Joe White of Topeka, Kan., jumped out of a moving car, suffering a severe head injury. He also is partly paralyzed.

"Joe is never going to be the same," his stepmother, Kristin White, told ABC. "He may never progress past being a 10-year-old mentally."

The teens perform for Web sites like VidMax, where they can post tapes. Erik Barath, the chief executive officer, said he pays up to $1,000 for the best tapes.